<!doctype html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>布局</title>
	<style type="text/css">
		body{
			font-size: 60px;
			color: #fff;
		}
		.box1{
			width: 800px;
			height: 200px;
			background: red url() 0 0 no-repeat;
		}
		.out{
			width: 800px;
			height: 200px;
		}
		.box2{
			width: 350px;
			height: 200px;
			background: blue url() 0 0 no-repeat;
			float: left;
			margin-right: 100px;
		}
		.box3{
			width: 350px;
			height: 200px;
			background: green url() 0 0 no-repeat;
			float: left;
		}
		.box4{
			width: 800px;
			height: 200px;
			background: yellow url() 0 0 no-repeat;
		}
	</style>
</head>
<body>
	<div class="box1">11111111111</div>
	<div class="out">
		<div class="box2">22222222222</div>
		<div class="box3">33333333333</div>
	</div>
	<div class="box4">4444444444444444444444</div>
</body>
</html>